The development of plasmid vectors useful for recombinant DNA genetics among microorganisms is well known. The editorial in Science, Vol. 196, April, 1977, gives a good summary of DNA research. This editorial is accompanied by a number of supporting papers in the same issue of Science.
Similar DNA work is currently being done on industrially important microorganisms of the genus Streptomyces. [Bibb, M. J., Ward, J. M., and Hopwood, D. A. 1978. "Transformation of plasmid DNA into Streptomyces at high frequency". Nature 274, 398-400]. Through plasmid DNA's have been detected in several Streptomycetes [Huber, M. L. B. and Godfrey, O. 1978. "A general method for lysis of Streptomyces species". Can. J. Microbiol. 24, 631-632.] [Schrempf, H., Bujard, H., Hopwood, D. A. and Goebel, W. 1975. "Isolation of covalently closed circular deoxyribonucleic acid from Streptomyces coelicolor A3(2)". J. Bacteriol. 121, 416-421.][Umezawa, H. 1977. "Microbial secondary metabolities with potential use in cancer treatment (Plasmid involvement in biosynthesis and compounds)". Biomedicine 26, 236-249.], [Malik, V. S. 1977. Preparative Method for the isolation of super-coiled DNA from a chloramphenicol producing Streptomycete. J. Antibiotics 30, 897-899.], only one Streptomycete plasmid has been physically isolated and extensively characterized in the literature [Schrempf, supra]. The existence of other plasmids in the genus Streptomyces has been inferred from reported genetic data as follows:
(1) Akagawa, H., Okanishi, M. and Umezawa, H. 1975. "A plasmid involved in chloramphenicol production in Streptomyces venezuelae: Evidence from genetic mapping". J. Gen. Microbiol. 90, 336-346. PA1 (2) Freeman, R. F. and Hopwood, D. A. 1978. "Unstable naturally occurring resistance to antibiotics in Streptomyces". J. Gen. Microbiol. 106, 377-381. PA1 (3) Friend, E. J. Warren, M. and Hopwood, D. A. 1978. "Genetic evidence for a plasmid controlling fertility in an industrial strain of Streptomyces rimosus". J. Gen. Microbiol. 106, 201-206. PA1 (4) Hopwood, D. A. and Wright, H. M. 1973. "A plasmid of Streptomyces coelicolor carrying a chromosomal locus and its inter-specific transfer". J. Gen. Microbiol. 79, 331-342. PA1 (5) Hotta, K., Okami, Y. and Umezawa, H. 1977. "Elimination of the ability of a kanamycin-producing strain to biosynthesize deoxystreptamine moiety by acriflavine". J. Antibiotics 30, 1146-1149. PA1 (6) Kirby, R., Wright, L. F. and Hopwood, D. A. 1975. "Plasmid-determined antibiotic synthesis and resistance in Streptomyces coelicolor". Nature 254, 265-267. PA1 (7) Kirby, R. and Hopwood, D. A. 1977. "Genetic determination of methylenomycin synthesis by the SCPI plasmid of Streptomyces coelicolor A3(2)". J. Gen. Microbiol. 98, 239-252. PA1 (8) Okanishi. M., Ohta, T. and Umezawa, H. 1969. "Possible control of formation of aerial mycelium and antibiotic production in Streptomyces by episomic factors". J. Antibiotics 23, 45-47.